22._____ computer has been proved to be _____ important aid in classroom teaching.
Zhangqiang is said ______ the experiment in the lab, but I can’t find him there.
I’ll go to meet you if I ________ free then.
Jane helped me with my work last week when I asked for leave. ______, I’ll invite her to have dinner with me.
Mo Yan has published dozens of novels, of _____some are very popular among Chinese readers, Red Sorghum, for example.
_____you have to do the job, you should try your best to do it well even though it may be very difficult for you.